1. Field of the Invention
This invention relates to sheaves and is particularly directed to a sheave that is adapted to be suspended and having counter-balancing weights mounted above the sheave for maintaining the sheave in continuous alignment with a plane passing through the cable, and thereby avoiding improper wear of the rope and inefficient operation of the sheave.
2. Description of the Prior Art
At present, for such activities for lowering wire cables to which sensors and instruments are attached, as in hydrographic work, a freely suspended sheave is employed. However, when the wire cable is not in the vertical plane because of towing angle, the present sheave is unable to correctly lie in the plane of the line, causing undue wear on the line and the sheave, and possibly causing the cable to jump off the sheave.
The present invention is able to avoid the above indicated mal-functioning of the sheave and wire cable by mounting counter-balancing weights above the suspended sheave or pulley.
Therefore a principal object of the present invention is to provide a suspended counter-balanced sheave that will lie in the plane of the lowering line extending from the sheave at all times and under varying conditions.
A further object of the present invention is to provide a suspended counter-balanced sheave that pivots readily to maintain the planes passing through the sheave and the line in superimposed alignment to prevent undue wear of the line and the pulley as the line sways from one side to the other.
A still further object of the present invention is to provide a suspended counter-balanced sheave with a pulley having a peripheral guard there-around to prevent the line from leaving the groove in the pulley and become wedged between the pulley and the mounting thereof.
With these and other objects in view, the invention will be best understood from a consideration of the following detailed description taken in connection with the accompanying drawings forming a part of this disclosure, with the understanding, however, that the invention is not confined to any strict conformity with the showing of the drawings but may be changed or modified so long as such changes or modifications mark no material departure from the salient features of the invention as expressed in the appended claims.